20120533376561 has 4 divisors (see below), whose sum is σ = 20120761668900. Its totient is φ = 20120305084224.

The previous prime is 20120533376557. The next prime is 20120533376597. The reversal of 20120533376561 is 16567333502102.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8757101377600 + 11363431998961 = 2959240^2 + 3370969^2 .

It is a cyclic number.

It is not a de Polignac number, because 20120533376561 - 2² = 20120533376557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20120533376521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114013916 + ... + 114190253.

It is an arithmetic number, because the mean of its divisors is an integer number (5030190417225).

Almost surely, 2^{20120533376561} is an apocalyptic number.

It is an amenable number.

20120533376561 is a deficient number, since it is larger than the sum of its proper divisors (228292339).

20120533376561 is an equidigital number, since it uses as much as digits as its factorization.

20120533376561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228292338.

The product of its (nonzero) digits is 680400, while the sum is 44.

Adding to 20120533376561 its reverse (16567333502102), we get a palindrome (36687866878663).

The spelling of 20120533376561 in words is "twenty trillion, one hundred twenty billion, five hundred thirty-three million, three hundred seventy-six thousand, five hundred sixty-one".